intra-martにてInternal Server Errorが表示される。

【現象】
intra-martにアクセスすると「Internal Server Error」になる。
resinのログ(jvm-app-0.log）には下記のようなメッセージが表示される。

```
[19-06-21 11:12:34.233] {resin-48} WebApp[production/webapp/default/imart] fail
[WARN] c.c.s.w.WebApp - [] java.lang.RuntimeException: resource: iwp/platform/schema/exists_table.sql is not found.
java.lang.RuntimeException: resource: iwp/platform/schema/exists_table.sql is not found.
	at jp.co.intra_mart.mirage.SqlManagerImpl.prepareNode(SqlManagerImpl.java:143)
	at jp.co.intra_mart.mirage.SqlManagerImpl.getSingleResult(SqlManagerImpl.java:218)
	at jp.co.intra_mart.mirage.ext.IntramartSqlManager.getSingleResult(IntramartSqlManager.java:39)
	at jp.co.intra_mart.mirage.SqlManagerImpl.getSingleResult(SqlManagerImpl.java:214)
	at jp.co.intra_mart.system.service.provider.updater.dao.ImSchemaUpdateDAO.existsTable(ImSchemaUpdateDAO.java:34)
	at jp.co.intra_mart.system.service.provider.updater.AbstractSchemaUpdater.update(AbstractSchemaUpdater.java:67)
	at jp.co.intra_mart.system.service.provider.updater.SystemDatabaseUpdater.update(SystemDatabaseUpdater.java:21)
	at jp.co.intra_mart.system.service.impl.ServiceControllerImpl.startCoordinator(ServiceControllerImpl.java:185)
	at jp.co.intra_mart.system.service.impl.ServiceControllerImpl.accept(ServiceControllerImpl.java:656)
	at jp.co.intra_mart.system.service.impl.ServiceControllerImpl.start(ServiceControllerImpl.java:126)
	at jp.co.intra_mart.foundation.service.ServiceController.start(ServiceController.java:49)
	at jp.co.intra_mart.system.servlet.PlatformServletContextListener.contextInitialized(PlatformServletContextListener.java:124)
	at com.caucho.server.webapp.WebApp.addListenerObject(WebApp.java:2181)
	at com.caucho.server.webapp.WebApp.callInitializers(WebApp.java:3534)
	at com.caucho.server.webapp.WebApp.startImpl(WebApp.java:3849)
	at com.caucho.server.webapp.WebApp.access$700(WebApp.java:209)
	at com.caucho.server.webapp.WebApp$StartupTask.run(WebApp.java:5413)
	at com.caucho.env.thread2.ResinThread2.runTasks(ResinThread2.java:173)
	at com.caucho.env.thread2.ResinThread2.run(ResinThread2.java:118)
[19-06-21 11:12:34.248] {main} java.lang.RuntimeException: resource: iwp/platform/schema/exists_table.sql is not found.
                       	at jp.co.intra_mart.mirage.SqlManagerImpl.prepareNode(SqlManagerImpl.java:143)
                       	at jp.co.intra_mart.mirage.SqlManagerImpl.getSingleResult(SqlManagerImpl.java:218)
                       	at jp.co.intra_mart.mirage.ext.IntramartSqlManager.getSingleResult(IntramartSqlManager.java:39)
                       	at jp.co.intra_mart.mirage.SqlManagerImpl.getSingleResult(SqlManagerImpl.java:214)
                       	at jp.co.intra_mart.system.service.provider.updater.dao.ImSchemaUpdateDAO.existsTable(ImSchemaUpdateDAO.java:34)
                       	at jp.co.intra_mart.system.service.provider.updater.AbstractSchemaUpdater.update(AbstractSchemaUpdater.java:67)
                       	at jp.co.intra_mart.system.service.provider.updater.SystemDatabaseUpdater.update(SystemDatabaseUpdater.java:21)
                       	at jp.co.intra_mart.system.service.impl.ServiceControllerImpl.startCoordinator(ServiceControllerImpl.java:185)
                       	at jp.co.intra_mart.system.service.impl.ServiceControllerImpl.accept(ServiceControllerImpl.java:656)
                       	at jp.co.intra_mart.system.service.impl.ServiceControllerImpl.start(ServiceControllerImpl.java:126)
                       	at jp.co.intra_mart.foundation.service.ServiceController.start(ServiceController.java:49)
                       	at jp.co.intra_mart.system.servlet.PlatformServletContextListener.contextInitialized(PlatformServletContextListener.java:124)
                       	at com.caucho.server.webapp.WebApp.addListenerObject(WebApp.java:2181)
                       	at com.caucho.server.webapp.WebApp.callInitializers(WebApp.java:3534)
                       	at com.caucho.server.webapp.WebApp.startImpl(WebApp.java:3849)
                       	at com.caucho.server.webapp.WebApp.access$700(WebApp.java:209)
                       	at com.caucho.server.webapp.WebApp$StartupTask.run(WebApp.java:5413)
                       	at com.caucho.env.thread2.ResinThread2.runTasks(ResinThread2.java:173)
                       	at com.caucho.env.thread2.ResinThread2.run(ResinThread2.java:118)
```

【原因】
 何らかの理由によりDBとの接続がうまくいっていない。